Chief has repeatedly commented about soil strucure, etc, not just wrt Riccarton, but many other tracks.
The top frequently chips out at Riccarton - whatever the rating - and while class horses definitely can find a 'kick' on the firmer conditions, the compacted nature of the ground means that some with joint and other issues, feel the jar badly.
I don't profess to be an expert, far from it, but I can remember back to times when firm/fast tracks were the order of the day during spring and summer racing, that's just what you got and the racing was super.
Back then it was the turf that provided the resilience and cushion, not the soil underneath. Nowadays, the brand of lush, soft green grass [ which looks admirable from the corporate boxes when mown in pretty strips ] has far less ability to cushion, a team of 500 kg animals at speed just cuts through the sappy, soft material to the dirt underneath, which must needs be dampened to provide the easing.
I recall, prior to one Easter meeting, back in the day of course manager Rob Lory [ mentioned in a post earlier ] I had walked around the track and happened to come across Rob doing much the same thing.
I commented upon the great sole of grass, and quipped ' leave the sprinklers on a bit more, Rob, my crew likes the softer stuff' to which he frowned at me and said ' I water for growth, NOT to affect the track conditions' .
Poor Rob copped a lot of flak for his efforts, probably his reserved and taciturn nature didn't help in that regards, but it wasn't until I spoke at length with Duncan Laing much later that I realised that he would have been following the 'best practice' manual left for him by Duncan.
Anyways, my boys coped very well with the prevailing conditions, finishing first, third and fourth in the Easter Classic [ then 2000m ].
And as for commented upon 'leader's bias ' yesterday, such a pattern is common when the rail is out.